Yes, Hall of Fame players can be picked on Day 3
In case you hadn't heard, the 2016 NFL Draft is coming up in two weeks. The Buffalo Bills have eight picks in the draft; two each in the fourth and sixth rounds, one each in the first, second, third, and fifth rounds, and none in the seventh round.
As with any draft, the later rounds will likely yield some quality players. Since the first common draft (after the AFL-NFL merger agreement) in 1967, there have been quality, tenured pro players selected at each position the Bills will be picking in this draft.